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Anupam's user avatar
Anupam's user avatar
Anupam
  • Member for 10 years, 11 months
  • Last seen more than a week ago
  • India
12 votes

Is it possible that $(ab)^{-1}$ is defined although $a^{-1},b^{-1}$ are not?

11 votes
Accepted

Elementary manipulation with elements of group

10 votes
Accepted

how to prove $f^{-1}(B_1 \cap B_2) = f^{-1}(B_1) \cap f^{-1}(B_2)$

5 votes
Accepted

Set of $n$ vectors spanning an $n$ - dim vector space implies set is a basis

4 votes
Accepted

Proof involving linear maps

4 votes

Show that Closure of a set is equal to the union of the set and its boundary

4 votes

When does a Möbius transformation map $\Im(z)>0$ to itself?

4 votes

Suppose $g$ is even and let $h=f \circ g$. Is $h$ always an even function?

4 votes

Are two finite groups of the same order always isomorphic?

3 votes

Prove that if a function $f: X\to Y$ continuous then its graph is closed

3 votes

Why, precisely, is $\{r \in \mathbb{Q}: - \sqrt{2} < r < \sqrt{2}\}$ clopen in $\mathbb{Q}$?

3 votes

Need help with set equivalence

3 votes

Let G be a group. If H is a normal subgroup in G, and K is a normal subgroup of H, when is K a normal subgroup of G?

2 votes

Proving a property of $L^\infty$ spaces

2 votes
Accepted

find all $x \in S_5$ such that $x^3 = (12)$

2 votes

A subgroup of $S_n$ contains only even permutations or half of them are even.

2 votes
Accepted

How to find the limit of recursive sequence?

2 votes

Best book of topology for beginner?

1 vote

A question about the dihedral group $D_n$

1 vote
Accepted

How to solve this Ratio problem

1 vote

How to find out if a function is surjective or injective?

1 vote

The prime order is cyclic

1 vote

Prove operation on binary relation

1 vote

limit point true false question

1 vote

why is any singleton set not open in the set of rational numbers

1 vote
Accepted

How to get average of Arun's weight?

1 vote
Accepted

What is a difference between these two definitions of $T_3$ space?

1 vote
Accepted

Find a sequence of Lipschitz continuous functions on $[0,1]$ whose uniform limit is $\sqrt{x}$.

1 vote

Closure of the orthogonal complement.

1 vote
Accepted

What is the harmonic conjugate of $v(x,y)=e^x$